Visceral Ischemia and Neutrophil Activation in Sepsis and Organ Dysfunction

Background. It has previously been shown that a rise in intraoperative neutrophil CD11b expression during supracoeliac cross-clamping is a marker for subsequent development of postoperative organ dysfunction. Prolonged visceral ischemia and increased aneurysm extent are associated with higher risks of morbidity and mortality after TAAA repair. This study investigates the relationship between visceral ischemia and neutrophil activation in sepsis and organ dysfunction following visceral reperfusion. Method. Fifty-one patients undergoing supracoeliac cross-clamping, 5 patients undergoing suprarenal clamping, and 8 patients undergoing infrarenal clamping for repair of aortic aneurysms were studied. Perioperative neutrophil CD11b expression was measured by flow cytometry. Results. There was significant correlation between visceral clamp time and intraoperative CD11b expression. More extensive aneurysms resulted in increased visceral clamp times and CD11b expression. There were no differences between bypass and non-bypass-assisted surgery with regard to neutrophil expression. There were increased clamp time in patients who developed severe sepsis and postoperative organ dysfunction. Differences in preoperative levels of CD11b expression were observed between groups and high levels of preoperative CD11b expression were observed in patients who died intraoperatively, in type II patients who went on to develop severe sepsis and organ failure, and in patients who developed multiple organ failure rather than single organ failure. Conclusion. Longer periods of visceral ischemia are associated with higher levels of intraoperative CD11b expression, severe sepsis, and organ failure. High preoperative levels of CD11b may identify an “at-risk” subset of patients.